Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 282140
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
340 PM CST SUN DEC 28 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 143 PM CST SUN DEC 28 2014

VERY LITTLE CHANCE FOR PRECIP IN THE SHORT TERM...PERHAPS SOME
ISOLATED SNOW FLURRIES. THE FOCUS WAS ON THE AMOUNT OF CLOUD COVER
AND THE COOLING TEMPERATURE TREND. THE BAND OF LOW CLOUDS TODAY
THAT SLOWLY DROPPED SOUTH ACROSS MN/WI IS ROUGHLY THE DEMARCATION
OF THE COOLER AIR TO THE NORTH AND SLIGHTLY MILDER AIR TO THE
SOUTH. THIS COLD FRONT WILL CONTINUE MOVING TO THE SOUTH TONIGHT
AS A NEARLY 1060MB HIGH BUILDS ACROSS THE NORTHERN ROCKIES AND
NORTHERN HIGH PLAINS...QUITE IMPRESSIVE MLSP RISES. WHILE THERE
SHOULD BE SOME MODIFICATION AS THE AIR MOVES SOUTH TONIGHT AND
TOMORROW...THE HIGH TEMPERATURES NEAR THE MN/CANADIAN ARE
INDICATIVE OF THE AIR MASS EXPECTED TO BE HERE TOMORROW. HIGHS
NEAR THE BORDER WERE NEAR ZERO TODAY...SO THE FORECAST AREA /AND
ESPECIALLY CENTRAL MN/ IS IN FOR A COLD DAY TOMORROW. TONIGHT`S
LOWS ARE COMPLICATED BY THE CLOUD COVER COMING OUT OF THE DAKOTAS.
THERE COULD BE A FAIRLY LARGE NORTH-SOUTH TEMPERATURE GRADIENT
ACROSS THE FORECAST AREA LATE TONIGHT. LIGHT SNOW IS POSSIBLE IN
SOUTHWEST MINNESOTA...BUT LITTLE TO NO SNOW IS EXPECTED TO REACH
THE FORECAST AREA.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 143 PM CST SUN DEC 28 2014

LARGE SCALE PATTERN EVOLUTION...
OVERALL THERE LOOKS TO BE MINIMAL CHANGE IN THE OVERALL LONGWAVE
PATTERN THROUGH THE FORECAST PERIOD... WITH AN UPPER RIDGE OFF THE
WEST COAST NORTH THROUGH ALASKA... AND A DEEP TROUGH OVER MUCH OF
THE NORTH AMERICAN CONTINENT. THIS WILL KEEP THINGS GENERALLY DRY
AND COLD OVER OUR AREA THROUGH THE PERIOD... ALTHOUGH THERE ARE A
FEW CHANCES FOR PCPN... AND UNCERTAINTY IN SPECIFICS TOWARD THE
END OF THE PERIOD.

FORECAST ITEM/S/ OF CONCERN...
THE COLD TEMPERATURES AND LOW WIND CHILLS THE NEXT SEVERAL
MORNINGS LOOK TO BE THE PRIMARY CONCERN... WITH A GOOD CHANCE THAT
THERE WILL EVENTUALLY NEED TO BE SOME WIND CHILL HEADLINES OVER
MUCH OF THE AREA... PARTICULARLY FOR MONDAY AND TUESDAY NIGHTS
INTO THE FOLLOWING MORNINGS. OTHERWISE... THE ONLY MEANINGFUL PCPN
CHANCES DON/T ARRIVE UNTIL THURSDAY AND BEYOND... AND AT THIS
POINT IT STILL APPEARS THE BULK OF MOISTURE AND PCPN WILL REMAIN
OUT OF OUR AREA.

MODEL DISCUSSION/PREFERENCES...
GUIDANCE IS IN FAIRLY GOOD AGREEMENT THROUGH THURSDAY... WITH
QUITE A BIT OF DIVERGENCE IN SOLUTIONS BEYOND THAT POINT. THE
ECMWF SHIFTED MARKEDLY FROM ITS PREVIOUS FORECASTS AFTER
THURSDAY... WITH IT NOW RETAINING A MUCH MORE SLOWLY MOVING CUTOFF
LOW OVER THE SOUTHERN CONUS OVER THE WEEKEND. THIS LEADS TO A MUCH
MORE SOUTHERLY TRACK WITH THE SYSTEM THAT THE GFS TAKES THROUGH
THE MID-MISSISSIPPI VALLEY AND LOWER GREAT LAKES SATURDAY-SUNDAY.
THE 12Z GFS HINTED TOWARD THIS CHANGE AS WELL... BUT NOT TO THE
DEGREE OF THE ECMWF. THE ENSEMBLE SOLUTIONS SHOW SIGNIFICANT
SPREAD... WHICH ISN/T SURPRISING... SUGGESTING THAT HAVING ANY
CONFIDENCE IN A PARTICULAR SOLUTION AT THIS POINT IN TIME DOESN/T
MAKE MUCH SENSE. SO... KEPT WITH A BLEND OF THE GFS/ECMWF/PREVIOUS
FORECAST FOR NOW.

SENSIBLE WEATHER EXPECTATIONS...
COLD AND DRY WEATHER IS EXPECTED MONDAY NIGHT THROUGH WEDNESDAY
NIGHT... WITH SOME MODERATION IN TEMPERATURE BEGINNING WEDNESDAY
NIGHT AS RETURN FLOW BRIEFLY GETS ESTABLISHED OVER THE AREA.
HOWEVER... A REINFORCING ARCTIC FRONT WILL DROP THROUGH THE AREA
ON THURSDAY... AND COULD BE ACCOMPANIES BY SOME LIGHT SNOW AS IT
DOES SO. WE/LL SEE SOME CHANCES FOR SNOW FROM FRIDAY INTO AT LEAST
THE FIRST HALF OF THE WEEKEND AS WARM ADVECTION POTENTIALLY SETS
BACK UP ACROSS THE AREA. HOWEVER... AS DISCUSSED ABOVE THERE ARE A
WIDE VARIETY OF SOLUTIONS AFTER THURSDAY... AND IT COULD EASILY
REMAIN MOSTLY COOL AND DRY. THE MAIN SYSTEM WILL BE AN AREA OF LOW
PRESSURE THAT LOOKS TO DEVELOP OVER THE FAR SOUTHERN PLAINS AND
LOWER MISSISSIPPI VALLEY FRIDAY INTO SATURDAY... WHICH WILL THEN
MOVE NORTHEAST. AT THIS POINT... IT WOULD PRIMARILY IMPACT
LOCATIONS WELL TO OUR EAST/SOUTHEAST... AND EVEN MORE-SO IF REALITY
WINDS UP CLOSER TO THE ECMWF SOLUTION.

DETAILED DISCUSSION FOR ITEM/S/ OF CONCERN...
LOWS ARE EXPECTED TO BOTTOM OUT BELOW ZERO BOTH MONDAY AND TUESDAY
NIGHTS... AND WITH THE SURFACE HIGH CENTERED WELL TO OUR WEST IT
LOOKS LIKE WE/LL BE ABLE TO MAINTAIN SOME WINDS EACH NIGHT. SO...
LOOKS LIKE WE/LL HAVE A PERIOD OF WIND CHILLS IN THE 15 TO 30
BELOW ZERO RANGE OVER MUCH OF THE AREA OVERNIGHT EACH NIGHT INTO
MID MORNING THE FOLLOWING MORNINGS. AT THIS POINT... FORECAST
VALUES AREN/T TOO EXTREME... BOTTOMING OUT IN THE 25 TO 30 BELOW
RANGE... BUT IT WILL CERTAINLY BEAR WATCHING IF TEMPERATURES GET
COOLER THAN GUIDANCE CURRENTLY SUGGESTS. HOWEVER... CURRENT VALUES
INDICATE THAT AT LEAST WIND CHILL ADVISORIES WILL BE NEEDED AS WE
GET CLOSER IN TIME.

FORECAST CONFIDENCE/UNCERTAINTY...
CONFIDENCE IS HIGH IN THE LIKELIHOOD OF WELL BELOW NORMAL
TEMPERATURES... WIND CHILLS COLDER THAN 20 BELOW AT NIGHT INTO
EARLY MORNING... AND DRY WEATHER INTO MIDWEEK. CONFIDENCE IS
ALSO HIGH THAT WE/LL SEE MODERATING TEMPERATURES OVER THE SECOND
HALF OF THE WEEK. CONFIDENCE IS LOW ON THE TIMING AND COVERAGE OF
SNOW FOR THE LATTER HALF OF THE WEEK AND UPCOMING WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 111 PM CST SUN DEC 28 2014

MVFR CEILINGS CONTINUE TO SLOWLY BREAK UP THIS AFTERNOON. NEARLY
ALL THE TAF SITES SHOULD BE VFR BY THIS AFTERNOON...AND THAT
SHOULD LAST THROUGHOUT THE NIGHT. THE EXCEPTION WOULD BE
KRWF...WHERE LOW CEILINGS IN SOUTHWEST MN COULD BUILD NORTH
TONIGHT. THERE IS ALSO A SLIGHT CHANCE OF LIGHT SNOW TONIGHT AT
KRWF. OTHERWISE...WE JUST EXPECT MID CLOUDS TONIGHT.

KMSP...

ONCE THE BROKEN 2500-3500FT DECK CLEARS THIS AFTERNOON. KMSP
SHOULD REMAIN IN THE CLEAR THIS EVENING AND TONIGHT WITH NO
AVIATION WEATHER CONCERNS.

/OUTLOOK FOR KMSP/

TUE...VFR. WINDS WNW 10 KTS.
WED...VFR. WINDS SW 15G25 KTS.
THU...VFR. SLIGHT CHANCE OF -SN AND MVFR. WINDS W 5-10KTS.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...
LONG TERM...
VIATION...CLF








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